Secure Firewall Threat DefenseApplication · Cisco
CVE-2019-1669
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA vulnerability in the data acquisition (DAQ) component of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured access control policies or cause a denial of service (DoS) condition. The vulnerability exists because the affected software improperly manages system memory resources when inspecting traffic. An attacker could exploit this vulnerability by generating specific traffic patterns for the software to inspect. A successful exploit could allow the attacker to exhaust system memory resources used for traffic inspection. Depending on the configuration, the FTD Software could fail open and cease to inspect traffic or fail closed and result in a DoS condition. This vulnerability may require manual intervention to restore the software.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA memory exhaustion vulnerability in the Data Acquisition (DAQ) component of Cisco Firepower Threat Defense allows an unauthenticated remote attacker to bypass access control policies or cause a denial of service. By sending specific traffic patterns, the attacker exhausts system memory resources used for traffic inspection, causing the software to fail open (ceasing inspection) or fail closed (DoS).
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Secure Firewall Threat DefenseApplication
= 6.3.0= 6.4.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Cisco FTD versionRun 'show version' or access the Firepower Management Center to view the Firepower Threat Defense version. Look for the exact version number in the output.Affected if The installed version is exactly 6.3.0 or exactly 6.4.0
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Verify DAQ module is activeCheck the Firepower Threat Defense configuration for Data Acquisition (DAQ) module usage. This may be visible in the running configuration or via 'show module' command output if available.Affected if The DAQ component is enabled and actively processing traffic inspection
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Check for memory exhaustion symptomsMonitor system memory usage via 'show memory' or equivalent command. Look for abnormally high memory consumption in the traffic inspection subsystem.Affected if System memory for traffic inspection is abnormally high or depleted, indicating potential exploitation
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Review traffic inspection failuresCheck system logs and event logs for patterns indicating fail-open (inspection bypass) or fail-closed (service denial) events coinciding with specific traffic patterns.Affected if Logs show inspection bypass events or DoS conditions that correlate with unusual traffic patterns
You are affected if your Cisco Firepower Threat Defense runs exactly version 6.3.0 or 6.4.0, the DAQ module is active, and memory exhaustion or inspection failures are observed.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply the Cisco software update/patch for CVE-2019-1669. If exploitation has occurred, manual intervention may be required to restore normal operation. Review access control policy configuration after patching to ensure policies are functioning correctly.
Fix this in Secure Firewall Threat Defense
Scoped from the published advisory
- Consultation4.0 h
- Implementation6.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,080.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-1669 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2019-1669 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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